Department of Geosciences, University of Padova, 35131, Padova, Italy.
Lithosphere Fluid Research Lab, Institute of Geography and Earth Sciences, Eötvös Loránd University, Budapest, H-1117, Hungary.
Nat Commun. 2020 Apr 7;11(1):1670. doi: 10.1038/s41467-020-15325-6.
Large Igneous Province eruptions coincide with many major Phanerozoic mass extinctions, suggesting a cause-effect relationship where volcanic degassing triggers global climatic changes. In order to fully understand this relationship, it is necessary to constrain the quantity and type of degassed magmatic volatiles, and to determine the depth of their source and the timing of eruption. Here we present direct evidence of abundant CO in basaltic rocks from the end-Triassic Central Atlantic Magmatic Province (CAMP), through investigation of gas exsolution bubbles preserved by melt inclusions. Our results indicate abundance of CO and a mantle and/or lower-middle crustal origin for at least part of the degassed carbon. The presence of deep carbon is a key control on the emplacement mode of CAMP magmas, favouring rapid eruption pulses (a few centuries each). Our estimates suggest that the amount of CO that each CAMP magmatic pulse injected into the end-Triassic atmosphere is comparable to the amount of anthropogenic emissions projected for the 21 century. Such large volumes of volcanic CO likely contributed to end-Triassic global warming and ocean acidification.
大火成岩省的喷发与许多显生宙大灭绝事件同时发生，这表明火山释放气体引发了全球气候变化，二者之间存在因果关系。为了全面了解这种关系，有必要约束释放的岩浆挥发物的数量和类型，并确定其来源深度和喷发时间。在这里，我们通过对熔体包裹体中保存的气体出溶气泡进行研究，为从中生代末期大西洋中部大火成岩省（CAMP）玄武岩中存在大量 CO 提供了直接证据。我们的结果表明，CO 的丰度以及至少部分脱气碳的地幔和/或中下地壳起源。深碳的存在是控制 CAMP 岩浆就位模式的关键因素，有利于快速喷发脉冲（每个脉冲持续数百年）。我们的估计表明，每个 CAMP 岩浆脉冲注入晚三叠世大气中的 CO 量与预计 21 世纪人为排放的量相当。如此大量的火山 CO 可能导致了晚三叠世的全球变暖与海洋酸化。
